JP6445862B2 - Buckling restraint brace - Google Patents

Description

  The present invention relates to a buckling-restrained brace and a buckling-restrained brace evaluation method that are incorporated in a structure and absorb vibration energy to dampen vibration during an earthquake or the like.

  In Patent Document 1, in a buckling restrained brace having a plate-shaped core material and a pair of constraining materials arranged opposite to each other along both surfaces of the core material, joints are provided at both ends of the core material. The joint portion of the core material is wider than the constraining material as a shape having a portion projecting in the width direction with respect to the other portions of the core material, and at both ends in the width direction of the joint portion having the width. A buckling restrained brace provided with reinforcing ribs is disclosed.

  In Patent Document 2, the collapse mechanism of the joint between the steel pipe column filled with concrete in the inner space and the steel beam is defined by the yield line and the flat plate portion surrounded by the yield line. In the method of estimating the yield strength of a steel tube-column joint that uses the yield line theory to derive the yield strength of the joint from the cross-sectional yield condition, the steel pipe column is formed with a thick tube thickness dimension. In order to determine the yield strength of the joint part by separately setting the pipe thickness dimension of the joint part and the pipe thickness dimension of the general part separately, the upper end part of the joint part is considered. It is disclosed that the yield strength is obtained by reflecting the distance between the upper end of the steel beam and the axial force acting on the steel pipe column in the yield line theory.

JP 2014-77336 A Japanese Patent Laid-Open No. 2001-41866

  However, in the conventional buckling restrained brace, when a standard product is used as the rectangular steel pipe, the width and thickness of the standard product are determined, so the axial force for designing the core material is desired to be a desired value. In addition, there are cases where a standard product that matches this cannot be prepared. In such a case, if a square steel pipe of one rank is used, other member designs are affected and the cost is increased. On the other hand, when a square steel pipe is produced as a special order, the cost is high. In addition, if a constraining material that cannot support the design axial force of the core material is used, and if the stiffening force in the weak axis direction of the core material is exceeded beyond the design axial force, local fracture occurs in the constraining material. Will end up.

  In view of the above circumstances, the present invention prevents buckling-restrained braces that do not cause local destruction in the restraint material that has received the stiffening force of the core material, and does not cause local fracture in the restraint material that has received the stiffening force of the core material. It is an object of the present invention to provide a method for evaluating a buckling restrained brace.

  In order to solve the above-described problem, the buckling restrained brace of the present invention has a core member having joint portions for joining to other members at both ends of the plate-like portion, and a weak axis direction of the plate-like portion. In a buckling restraint brace provided with restraint members arranged to face each orthogonal surface, an insertion plate is provided between the plate-like portion and the restraint material in contact with the restraint material. It is characterized by that.

  If it is said structure, the said local material can be improved with the said restraint material and the said insertion board, The said restraint material and the said insertion board which received the stiffening force of the weak axis direction of the said core material It is possible to prevent local destruction from occurring. And since the local yield strength which is insufficient with the said restraint material can be supplemented with the said insertion board, a standard product can be used as the said restraint material, and cost can be suppressed.

  The constraining material is formed of a square steel pipe, and the square steel pipe may have a corner portion having a curved surface region at an intersection of each surface portion.

  The said insertion board may be fixed to the said restraint material in places other than the surface where the said insertion board and the said restraint material contact. When the insertion plate and the restraining material are fixed, the work of assembling the buckling restraint brace becomes easier as compared with the state where the insertion plate and the restraining material are separated.

  Each insertion plate may be divided into a plurality of pieces.

Further, the buckling restraint brace evaluation method of the present invention opposes the core material having joint portions for joining with other members at both ends of the plate-like portion, and each surface in the weak axis direction of the plate-like portion. A buckling restraint brace evaluation method in which an insertion plate is provided in contact with the restraint material between the plate-like portion and the restraint material. And
The constraining material is made of a square steel pipe, and the square steel pipe has a corner portion having a curved surface area at the intersection of each surface portion thereof,
By simplifying the corner portion having the curved surface region as a planar region, the cross section of the square steel pipe is represented by an octagon, and the yielding wire theory is used to stiffen the square steel pipe with the stiffening force in the weak axis direction of the core material. It is assumed that a boat-bottom-shaped buckling occurs in the insertion plate, the width of the boat-bottom buckling is an unknown number x, and each of the square steel pipe and the insertion plate at the center and both ends of the boat-bottom shape The rotation angle of the yield line is a function of the unknown x, and the rotation angle of the yield line of the square steel pipe at the simplified location in the plane region is a function of the unknown x.
The total local strength obtained by adding the local strength of the rectangular steel pipe obtained using the above function and the local strength of the insert plate obtained using the above function, taking into account the safety factor or the safety factor. The buckling restrained brace is evaluated depending on whether or not the stiffening force in the weak axis direction of the core material is exceeded.

  If it is said evaluation method, since the cross section of the said square steel pipe is represented by an octagon by simplifying the corner | angular part which has the said curved surface area | region as a plane area, evaluating a buckling restraint brace with a comparatively simple numerical formula Is possible.

Further, the buckling restraint brace evaluation method of the present invention opposes the core material having joint portions for joining with other members at both ends of the plate-like portion, and each surface in the weak axis direction of the plate-like portion. A buckling restraint brace evaluation method in which an insertion plate is provided in contact with the restraint material between the plate-like portion and the restraint material. And
It is assumed that the bottom bottom buckling occurs in the rectangular steel pipe as the restraint material and the insertion plate due to the stiffening force in the weak axis direction of the core material, and the width of the bottom buckling is an unknown x, the square steel pipe the yield stress of the _R F _y, the yield stress of _P F _y of the inner挿板, width _{B R} of the square tube, the width of the inner挿板_{B P,} the plate thickness of the square tube _{t R,} the inner挿板the thickness of the as t _p, the circular constant π,


The unknowns x represented by formula above number 13, to evaluate the buckling restrained brace based on calculation formula obtained by substituting the equation for determining the local plastic Strength P _R represented by the number 11 of the It is characterized by.

  If it is said evaluation method, it will become possible to evaluate a buckling restraint brace with said comparatively simple numerical formula, for example, an evaluation result can be simply taken out using general spreadsheet software.

Further, in any of the above-described buckling-restraining braces, it is assumed that a boat-bottom buckling occurs in the rectangular steel pipe as the restraining material and the insertion plate due to the stiffening force in the weak axis direction of the core material. The width of the bottom buckling is unknown x, the yield stress of the square steel pipe is _R F _y , the yield stress of the insert plate is _P F _y , the width of the square steel pipe is B _R , and the width of the insert plate is B _P The thickness of the square steel pipe is t _R , the thickness of the insertion plate is t _p , and the circumference is π,



The unknowns x represented by formula above-mentioned number of 13, based on the local plastic Strength P Request _R calculation formula obtained by substituting the equations represented by the number 11 of the, no buckling above auxiliary Herculean strength An inserted insertion plate may be provided.

  If it is this invention, it will become easy to use members, such as a ready-made square steel pipe, as a restraint material, and it will not cause a local destruction to the restraint material which received the stiffening force of the core material, without causing cost increase. Can be. In addition, the buckling restraint brace evaluation method of the present invention has an effect that the buckling restraint brace can be evaluated with a relatively simple mathematical formula.

It is the general | schematic longitudinal cross-sectional view which showed the buckling restraint brace of embodiment of this invention, Comprising: The figure (A) shows the completion state, The figure (B) has shown the decomposition | disassembly state. 1A is a perspective view showing the buckling restrained brace of FIG. 1, and FIG. 1B is a perspective view showing a core material. FIG. 2A is a plan view showing a joint portion of the buckling restrained brace of FIG. 1, and FIG. 2B is a side view thereof. It is the schematic perspective view which showed the welding location of the restraint material and insertion board of the buckling restraint brace of FIG. 1A is an explanatory diagram showing that the restraining material and the insertion plate receive the stiffening force of the core material in the buckling restrained brace of FIG. 1, and FIG. 1B shows the weak axis direction of the core material. It is explanatory drawing which showed the relationship between a deformation | transformation and stiffening force. It is explanatory drawing which showed the local destruction mechanism of the restraint material of the buckling restraint brace of FIG. 1, and an insertion board. It is the flowchart which showed the evaluation method of the buckling restraint brace of FIG. It is the schematic which illustrated the joining by the joining plate of the junction part of a buckling restraint brace of FIG. 1, and another member, and the figure (A) is a top view, The figure (B) is a side view, The figure (C). Is a cross-sectional view. It is the schematic which illustrated the joining by the joining plate of the junction part of a buckling restraint brace of FIG. 1, and another member, and the figure (A) is a top view, The figure (B) is a side view, The figure (C). Is a cross-sectional view. It is the schematic which illustrated the joining by the joining plate of the junction part of a buckling restraint brace of FIG. 1, and another member, and the figure (A) is a top view, The figure (B) is a side view, The figure (C). Is a cross-sectional view.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 1 (A), FIG. 1 (B), FIG. 2 (A) and FIG. 2 (B), the buckling restraint brace 1 of this embodiment includes a core material 11, a restraint material 12, An insertion plate 13, an unbond material 14, a width direction stiffener 15, and a reinforcing plate 16 are provided.

  The said core material 11 consists of a steel plate, for example, and has the junction part 11b at the both ends of the plate-shaped part 11a. The plate-like portion 11a has a constant width, and the joint portion 11b at both ends is wider than this. The joint portion 11b has a substantially H-shaped cross section perpendicular to the longitudinal direction of the plate-like portion 11a, and a joining plate can be placed on the joint portion 11b to join to another member. Holes through which the bolts for joining are inserted are formed at locations that serve as flange portions and web portions at the joint portion 11b. Further, in the boundary region from the plate-like portion 11a to the joint portion 11b, the width of the plate-like portion 11a gradually increases in a curved shape so that the shape changes to form the web portion of the joint portion 11b. .

  The restraint member 12 is a square steel pipe having a rectangular cross section. This rectangular steel pipe has a first surface portion that becomes the long side of the rectangle and a second surface portion that becomes the short side. The restraint member 12 is disposed so that the first surface portion faces each surface orthogonal to the weak axis direction (the plate thickness direction of the core member 11) of the plate-like portion 11 a of the core member 11. Both ends in the longitudinal direction of the constraining material 12 reach the web portion in the joint portion 11b beyond the curved spread portion. Moreover, the said square steel pipe has a corner | angular part which has a curved surface area | region (R part) in the cross | intersection location of each surface part.

The insertion plate 13 is made of a steel plate, and is provided between the plate-like portion 11 a and each restraining material 12. And the said insertion board 13 is contacting the 1st surface part of the said square steel pipe which is the said restraint material 12. FIG. Moreover, the said insertion board 13 has the width | variety corresponded to the length between the surfaces of the 2nd surface part of the said square steel pipe. Of course, not limited to such a width, the insertion plate 13 has a width not more than the length between the surfaces of the second surface portion of the rectangular steel pipe and a width not less than the width of the first surface portion other than the curved surface region. May be. Here, the width of _{B R} a square steel, width _{B P} inner挿板13, when the plate thickness of the square tube and _{t R,} the width _{B P} of the inner挿板_13, B _{R -5t} R ≦ it can be expressed as _{B P} ≦ B _R (see FIG. 6). Incidentally, the width B _R of the square tube, a short side direction of the length in a plane intersecting the weak axis direction of the core member 11, the square tube as the said restraint material 12 between the surfaces of the second face It becomes length.

  Further, pin-shaped detent protrusions 11 c that protrude on both surfaces of the core material 11 are provided on the center side in the longitudinal direction of the core material 11 and on the center side in the width direction. The slip prevention protrusion 11 c is inserted into the hole provided in the first surface portion inside the restraining material 12 and the hole formed in the insertion plate 13 when the buckling restraining brace 1 is assembled. The slip prevention protrusion 11c is made of a steel material such as a steel rod, and is inserted and joined into a hole provided in the core material 11, for example.

  Further, the core material 11 is provided with intermediate slits 11d for adjusting the proof stress on both sides in the length direction of the core material 11 sandwiching the displacement preventing projection 11c. In each intermediate slit 11d, an internal deformation preventing material made of steel or the like serving as a spacer is inserted so as to be movable relative to the intermediate slit 11d in the longitudinal direction. The internal deformation preventing material is interposed between the insertion plates 13 and 13 and is regulated by the insertion plates 13 and 13 in the depth direction of the intermediate slit 11d.

  The unbond material 14 is provided between the plate-like portion 11a and the insertion plate 13, and when the plate-like portion 11a receives a compressive force with the thickness of the unbond material 14 as a clearance, the unbonded material 14 is wavy. Deformation occurs. The unbond material 14 is made of, for example, butyl rubber.

  The width direction stiffener 15 is made of a steel plate, and restrains deformation of the core material 11 in the width direction (in the composition plane). The width direction stiffener 15 is stretched between the second surface portions of the restraining materials 12 and 12 and is fixed to the restraining materials 12 and 12 by a welded portion 15a. Further, as shown in FIGS. 3 (A) and 3 (B), a U-shaped cut portion 15b having an opening on the end portion side is formed at the end portion of the width direction stiffener 15. The curved region of the plate-like portion 11a is located in the cut portion 15b. By forming the cut portion 15b, a portion near the joint portion 11b in the core material 11 is not constrained in the width direction and becomes a non-stiffening section (hatched portion). In this way, by fixing the width direction stiffener 15 to the restraint member 12 and providing a non-stiffening section in the strong axis direction in the vicinity of the joint portion 11b in the core member 11, the buckling restraint brace 1 at the time of large deformation. A bending hinge is formed (see the white arrow in the figure), and the restraining material 12 and the insertion plate 13 are prevented from being damaged by bending or axial force entering the restraining material 12 and the insertion plate 13.

  The reinforcing plate 16 is made of a steel plate, is passed between the flange portions of the joint portion 11b in the core material 11, and is welded and fixed to the flange portion. The reinforcing plate 16 is provided so as to overlap the non-stiffening section (the cut portion 15b). When the end portion of the restraint member 12 opens in the weak axis direction of the core member 11, the end portion of the buckling restraint brace 1 is damaged. However, the damage is prevented by providing the reinforcing plate 16. Is done. Further, by providing the reinforcing plate 16 so as to overlap the non-stiffening section, the cut portion 15b can be hardly seen.

  As shown in FIG. 4, a portion other than the surface where the insertion plate 13 and the restraining material 12 contact, for example, four corners between the corner of the restraining material 12 and the insertion plate 13. You may fix the said insertion board 13 to the said restraint material 12 by providing the welding part 17 in the location used as a recess.

  With the above configuration, the overall local yield strength of the restraint member 12 and the insertion plate 13 can be improved, and the restraint member 12 that has received the stiffening force in the weak axis direction of the core member 11 and The internal insertion plate 13 can be prevented from causing local destruction. And since the local yield strength insufficient with the said restraint material 12 can be supplemented with the said insertion board 13, a standard product can be used as the said restraint material 12, and manufacturing cost can be suppressed.

  When the insert plate 13 is fixed to the restraint member 12 at a place other than the surface where the insert plate 13 and the restraint member 12 are in contact with each other, the insert plate 13 and the restraint member 12 are separated. Compared to the state in which the buckling restraint brace 1 is assembled, the operation of assembling the buckling restraint brace 1 becomes easier. It is also possible to replace the welded part 15a with an adhesive part made of an adhesive.

  Moreover, each insertion board 13 may be divided | segmented into plurality. For example, the insertion plate 13 may be divided in the thickness direction, and a plurality of thin insertion plates may be stacked. The insertion plate 13 may be divided in the width direction, and a plurality of insertion plates having the same thickness may be arranged side by side.

Next, a method for evaluating a buckling restrained brace will be described. The steel pipe and insert plate of the constraining material should be designed so that local fracture in the weak axis direction of the core material does not occur, satisfying the following equation. In Equation 1 below, the P _Ry is a local strength of the restraining member (RHS and inner挿板13), the reduction factor of the local yield strength R _L (safety factor). Also, C ₁ is the complement Herculean strength to the core material weak axis. In other words, as shown in the equation (1), local fracture is prevented by increasing the proof stress of the restraint material (which means the whole of the square steel pipe and the insertion plate) rather than the stiffening force due to deformation of the core material 11. To do.

  Although there is a general calculation formula for the stiffening force, there is no general formula for local deformation of the constraining material. In the actual design, the local yield strength of the steel pipe will be reduced by about 0.8 times to provide a safety factor against local failure. The following is a general formula for calculating the stiffening force due to deformation of the core material.

The core material 11 exhibits a buckling in a higher mode within the clearance with respect to the compressive force. At this time, a force C ₁ (stiffening force) that pushes the restraining material out of the plane in the weak axis direction of the core material 11 is generated. A failure mode in which the plate element of the restraint material bends and yields due to the stiffening force C _{1 to} cause local out-of-plane deformation is called local failure in the core weak axis direction. To prevent local destruction of the restraining member is local yield strength P _Ry constraining material must be greater than the complement Herculean strength C _1. Complement Herculean strength C _1, from the balance condition of the power system shown in FIG. 5 (A), it is expressed by the following equation.

Here, 2s is the clearance between the core material 11 and the restraint material (thickness of the unbond material 14), and _ln1 is the wavelength of the higher-order buckling mode in the weak axis direction of the core material 11. It is assumed that when the axial force of the core 11 reaches the yield axial force, a buckling mode as shown in FIG. 5 (B) occurs, and this shape does not change even when the yield strength increases due to strain hardening or repetition. In this case l _n1 is in equi-spaced corresponding tangent modulus load N _y are obtained from the following equation.

Here, _Et is a tangent coefficient. Also, I _s is the second moment of the weak axis of the core 11, it is expressed by the following equation.

Here, _{B h} is the width of the core 11, _{B s} is the width of the slit 11d, _{t s} is the thickness of the core 11. Tangent modulus E _t by using the strain hardening coefficient e _t is expressed by the following equation. The strain hardening coefficient was set to 0.05 with reference to past literature.

The sum of the “local strength of the constraining material 12 that is a square steel pipe” and the “local strength of the insert plate 13” is defined as “constraining material local strength” (total local strength).

“Local strength of the constraining material 12 that is a square steel pipe” is that when the plate thickness of the square steel pipe is t _R , the AE line is uniformly lowered by 2 t _R when the stiffening force is applied to the AE line in FIG. The deformation of the square steel pipe is assumed so that the square steel pipe is deformed into a ship bottom shape. By flattening the curved corners of the square steel pipe to form an octagonal shape, it is possible to easily calculate the deformation state of the curved surface of the steel pipe corner, which is originally complicated. The width of the ship bottom shape is an unknown number x, and is calculated after establishing an energy balance equation based on various parameters.

  In FIG. 6, the solid line in the “square steel pipe collapse mechanism (cross-sectional view)” indicates the center of the plate thickness of the square steel pipe, and also shows the flattened portion of the curved corner of the square steel pipe. The D point, the E point, and the F point in the “square steel pipe collapse mechanism (plan view)” indicate the center part in the width direction of the first surface portion of the square steel pipe, and are arranged in the longitudinal direction of the square steel pipe. Point A is the point closest to the second surface portion in the flattened portion, and points B and D are points closest to the first surface portion in the flattened portion. The AE line, AB line, and AC line do not pass through the curved corners of the square steel pipe, but are straight lines that pass through the flattened portion. In addition, point J, point K, and point L in the “insertion plate collapse mechanism” (plan view) indicate the center in the width direction of the insert plate 13, and point G is aligned in the longitudinal direction of the insert plate 13. , H point and I point indicate the width direction edge of the insertion plate 13.

  “Local strength of insert plate 13” means that when a stiffening force acts on the HK line in FIG. 6, the three yield lines (bends) of GJ, HK and IL are “local strength of steel pipe” Assuming that they occur in the same range, the yield strength is calculated using a simple formula. For the derivation of the equation after assuming the collapse mechanism, the general concept of yield line theory can be used.

P _RY is the restraint member local Strength (sum of each local strength of RHS and inner挿板) is calculated using the yield line theory. As shown in FIG. 6, the auxiliary Herculean strength C ₁ is that the out-of-plane deformation δ act occurs. Here, δ is set equal to the radius of curvature 2t _R of the corner of the square steel pipe.

  In consideration of symmetry, half of the collapse mechanism in FIG. 6 is considered. The rotation angle (θ) of each yield line (AB, AE, etc.) is shown below.

Here, l _AB is the length of the yield line AB. Further, _{t p} is the thickness of the inner挿板13. The value of x is unknown and is determined under the condition that the internal work is minimum. The total plastic moment _R M _p of the square steel pipe per unit length in the yield line and the total plastic moment _P M _y of the insert plate 13 per unit length in yield are given by the following equations.

Here, _R F _y is the yield stress level of the square steel pipe, _P F _y is the yield stress level of the insert plate 13, and the internal work at each yield line is given by the following equation. Here, l is the length of each yield line (AB, AE, etc.).

Here, _{B R} is the width of the square tube, the _{B P} is the width of the inner挿板13.
The total E of internal work on the yield line is expressed by the following equation.

Local plastic Strength and P _R, gives the external work W by the following equation.

Placing equal the external work and internal work, local plastic Strength P _R is given by the following equation.

The local yield strength _PRy is given by the following equation. It is not limited to 2/3 times.

When the local yield strength _PRy is differentiated by x and set to x = 0, the unknown x is expressed by the following equation.

_R F _y : Yield stress degree of square steel pipe
_P F _y : Yield stress degree of the insert plate B _R : Width of the square steel pipe B _P : Width of the insert plate t _R : Plate thickness of the square steel pipe t _p : Plate thickness of the insert plate π: Circumferential ratio

By substituting x determined by the equation (13) into the equation (12), the local yield strength _PRy is determined. The buckling-restrained brace 1 is evaluated in light of the local yield strength _PRy thus obtained according to the equation (1).

  That is, the evaluation method of the buckling restrained brace includes the core material 11 having the joint portions 11b for joining to other members at both ends of the plate-like portion 11a, and the plate-like portion 11a of the core material 11. A constraining material 12 disposed to face each surface in the weak axis direction, and an insertion plate 13 is in contact with the constraining material 12 between the plate-like portion 11a and the constraining material 12. This is a method for evaluating the buckling restrained brace 1 provided.

And the said restraint material 12 consists of a square steel pipe, and the said square steel pipe assumes that the corner | angular part which has a curved surface area | region in the cross | intersection location of each surface part.

  Then, as shown in the flowchart of FIG. 7, the cross section of the square steel pipe is modeled as an octagon by simplifying the corner portion having the curved surface region as a plane region (step S1).

  Then, using the yield line theory, it is assumed that the bottom bottom buckling occurs in the square steel pipe and the insertion plate by the stiffening force in the weak axis direction of the core, and the width of the bottom bottom buckling is An unknown number x, the rotation angle of the yield line of each of the square steel pipe and the insertion plate at the center of the boat bottom shape as a function of the unknown x, and the square shape at a simplified location in the plane region The rotation angle of the yield line of the steel pipe is set as a function of the unknown x (step S3).

Obtaining a local strength of the RHS determined using the above function, by summing the local yield strength of the inner挿板obtained using the above function, the local yield strength P _{Ry (the} total local yield strength) (step S4). Then, it is determined whether or not the local yield strength _PRy exceeds the _stiffening force (C ₁ ) in the weak axis direction of the core material 11 with or without taking into account the safety factor. (Step S5). If the local yield strength P _Ry is exceeds the auxiliary Herculean strength (C _1), a proper, is unsuitable properties otherwise.

If the program for substituting the equation representing x in equation (13) into the equation x for obtaining the local yield strength _PRy of equation (12) or the mathematical formula obtained by substitution is stored in a personal computer or the like, the insertion plate 13 An evaluation result can be obtained simply by inputting the thickness of the sheet. Since the above program or mathematical expression is simple, it can be described using general spreadsheet software.

  If it is the said evaluation method, the cross section of the said square steel pipe was represented by the octagon by simplifying the corner | angular part which has the said curved surface area | region as a plane area | region, and a buckling restraint brace is evaluated by a comparatively simple numerical formula. For example, an appropriate thickness of the insertion plate 13 can be easily obtained using general spreadsheet software. In addition, if the said insertion board 13 is divided | segmented into the thickness direction and it is the structure which laminates | stacks the insertion board of several thin board thickness, the proof stress term of an insertion board will only increase by the number of sheets, and a big change Absent.

And the buckling restraint brace 1 of this embodiment is provided with the insertion board 13 which satisfy | fills the conditions which become appropriate by judgment of the said step S5. That is, buckling restrained brace 1 of this embodiment, the unknowns x represented by formula above number 13, obtained by substituting the equation for determining the local plastic Strength P _R represented by the number 11 of the calculation An insertion plate 13 that is not buckled by the stiffening force based on the equation is provided.

  An attachment plate is used for joining the joint 11b and other members. For example, in the example shown in FIGS. 8A, 8B, and 8C, the flange plate 2 and the web plate 3 are used as accessory plates. The flange plate 2 is provided so as to sandwich the flange portion from above and below in the drawing at a portion that becomes the flange portion of the joint portion 11b, and is fixed by bolts and nuts. Similarly, the web plate 3 is provided at a portion to be the web portion of the joint portion 11b so as to sandwich the web portion from the left and right in the drawing, and is fixed by bolts and nuts. This joining is used when the design axial force is large. In the joining shown in FIG. 8, for example, when a square steel pipe having a width of about 60 mm is used as the restraining material 12, there arises a problem that a bolt cannot be accommodated.

  Therefore, as shown in FIGS. 9A, 9B, and 9C, in the portion that becomes the web portion of the joint portion 11b, the cross section is approximately T so that the web portion is sandwiched from the left and right in the drawing. A character-shaped member 4 is arranged, and the member 4 is fixed by bolts and nuts. By not using a joining plate in the part which becomes the flange part of the joining part 11b, even when a square steel pipe having a width of about 60 mm is used as the restraining material 12, a bolt is accommodated. This joining is used when the design axial force is small.

  Further, in the examples shown in FIGS. 10A, 10B, and 10C, the cross-section of the web portion of the joint portion 11b is substantially cross-sectional so that the web portion is sandwiched from the left and right in the drawing. A character-shaped member 5 is arranged, and the member 5 is fixed by bolts and nuts. Even in the case where a square steel pipe having a width of about 60 mm is used as the constraining material 12, the bolts can be accommodated by not using a joining plate in the part that becomes the flange part of the joining part 11 b. This joining is also used when the design axial force is small.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

DESCRIPTION OF SYMBOLS 1 Buckling restraint brace 11 Core material 11a Plate-shaped part 11b Joint part 12 Restraint material 13 Insertion board 14 Unbond material 15 Width direction stiffener 16 Reinforcement board

Claims (3)

A buckling comprising: a core member having joint portions for joining to other members at both ends of the plate-like portion; and a restraining material arranged to face each surface orthogonal to the weak axis direction of the plate-like portion. In the restraint brace, an insertion plate is provided between the plate-like portion and the restraint material in contact with the restraint material,
The constraining material is made of a square steel pipe, and the square steel pipe has a corner portion having a curved surface area at the intersection of each surface portion thereof,
A buckling characterized in that a welded portion for fixing the restraint material and the insert plate is provided between a surface of the insert plate that is in contact with the restraint material and a corner of the restraint material. Restraint brace. The buckling restraint brace according to claim 1 , wherein each insertion plate is divided into a plurality of pieces. In the buckling restrained brace according to claim 1 or 2 , the bottom bottom buckling occurs in the square steel pipe and the insertion plate as the restraining material by the stiffening force in the weak axis direction of the core material. The buckling width of the boat bottom shape is unknown x, the yield stress level of the square steel pipe is _R F _y , the yield stress level of the insertion plate is _P F _y , the width of the square steel pipe is B _R , and the width of the insertion plate the B _P, the plate thickness of the square tube t _R, the thickness of the inner挿板t _p, the circular constant and [pi,


The unknowns x represented by formula above-mentioned number of 13, based on the local plastic Strength P Request _R calculation formula obtained by substituting the equations represented by the number 11 of the, no buckling above auxiliary Herculean strength A buckling-restraining brace characterized in that an inserted insertion plate is provided.